pixels.cpp

Vc.Net入门与提高源码

// Pixels.cpp : Implementation of CPixels
#include "stdafx.h"
#include "Picture.h"
#include "Pixels.h"
#include "Bitmap.h"
#include "Pixel.h"

/////////////////////////////////////////////////////////////////////////////
// CPixels

typedef CComEnum<IEnumVARIANT, &IID_IEnumVARIANT, VARIANT,
                        _Copy<VARIANT> > VarArrEnum;

STDMETHODIMP CPixels::get__NewEnum(IUnknown **pVal)
{
    // Create an array of VT_DISPATCH for each pixel
    HRESULT hr;
    long height = m_pBitmap->m_height;
    long width = m_pBitmap->m_width;
    long iVariant = 0;
    
    VARIANT* pVars = new VARIANT[width*height];
    if (pVars == NULL) return E_OUTOFMEMORY;

    // Create a pixel in a VT_DISPATCH for each pixel of the array
    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < width; x++)
        {
            // Create this pixel object
            VariantInit(&pVars[iVariant]);
            pVars[iVariant].vt = VT_DISPATCH;
            hr = get_Pixel(x, y, 
                (IPixel**) &pVars[iVariant++].pdispVal);

            // Abort creation if anything failed
            if (FAILED(hr))
            {
                delete pVars;
                return hr;
            }
        }
    }

    // Create a pixel for each of the bitmap and add it to the
    // collection
    CComObject<VarArrEnum>* pPixelsColl;
    hr = CComObject<VarArrEnum>::CreateInstance(&pPixelsColl);
    if (SUCCEEDED(hr))
    {
        if (SUCCEEDED(hr = pPixelsColl->Init(
            pVars, pVars + (width*height), NULL, AtlFlagCopy)))
        {
            hr = pPixelsColl->QueryInterface(pVal);
        }
    }

    // Free our local copy of the VARIANT array
    delete pVars;
    return hr;
}

STDMETHODIMP CPixels::get_Count(long *pVal)
{
    // Return the number of pixels in this bitmap
    *pVal = m_pBitmap->m_width * m_pBitmap->m_height;
    return S_OK;
}

STDMETHODIMP CPixels::get_Color(long x, long y, baseColors *pVal)
{
    // Get a pixel color
    HRESULT hr;
    if (SUCCEEDED(hr = m_pBitmap->TestCoordinates(x, y)))
    {
        // Merge the 4 bits into the pixel's byte
        DWORD dwOffset = y * CBROW(m_pBitmap->m_width) + x / 2;
        if (x % 2)
            *pVal = (baseColors)
                (m_pBitmap->m_bitmap[dwOffset] & 0x0F);
        else
            *pVal = (baseColors)
                ((m_pBitmap->m_bitmap[dwOffset] & 0xF0) >> 4);
    }
    return S_OK;
}

STDMETHODIMP CPixels::put_Color(long x, long y, baseColors newVal)
{
    // Change a pixel color
    HRESULT hr = S_OK;
    if (FAILED(hr = m_pBitmap->TestCoordinates(x, y)))
    {
        if (VARIANT_TRUE == m_pBitmap->m_bAutoSize)
        {
            // If we are in AutoSizeed mode, update bitmap size
            hr = m_pBitmap->UpdateSize(
             (x>=m_pBitmap->m_width ? x+1 : m_pBitmap->m_width), 
             (y>=m_pBitmap->m_height ? y+1 : m_pBitmap->m_height));
        }
        else return hr;
    }

    // Calculate the offset in the bitmap data where to place the 
    // pixel and set the baseColor into the existing byte
    DWORD dwOffset = y * CBROW(m_pBitmap->m_width) + x / 2;
    if (x % 2) 
       m_pBitmap->m_bitmap[dwOffset] = 
            (m_pBitmap->m_bitmap[dwOffset] & 0xF0) | newVal;
    else
       m_pBitmap->m_bitmap[dwOffset] = 
            (m_pBitmap->m_bitmap[dwOffset] & 0x0F) | (newVal << 4);
    
    return S_OK;
}

STDMETHODIMP CPixels::get_Pixel(long x, long y, IPixel **pVal)
{
	// Get a pixel pointer from coordinates
    HRESULT hr;
    CComObject<CPixel>* pPixel;
    if (SUCCEEDED(hr=m_pBitmap->TestCoordinates(x,y)) &&
        SUCCEEDED(hr=CComObject<CPixel>::CreateInstance(&pPixel)))
    {
        // Set pixel properties
        pPixel->m_row = x;
        pPixel->m_col = y;
        if (SUCCEEDED(hr=get_Color(x, y, &pPixel->m_color)))
        {
            // Set the pixel in read-only
            pPixel->m_bReadOnly = true;

            // Return the object
            hr = pPixel->QueryInterface(pVal);
        }
    }
    
	return hr;
}

STDMETHODIMP CPixels::put_Pixel(long x, long y, IPixel *newVal)
{
	// Set the pixel color at the specified coordinates
    HRESULT hr;
    baseColors color;
    if (SUCCEEDED(hr = m_pBitmap->TestCoordinates(x, y)) && 
        SUCCEEDED(hr = newVal->get_Color(&color)) )
            hr = put_Color(x, y, color);

	return hr;
}